The semiconductor industry has relied on scaling/reducing device feature size in order to boost performance and increase transistor density. The continued device performance improvement due to scaling has seen the introduction of unique technologies such as semiconductor on insulator (e.g., silicon on insulator (SOI) and germanium on insulator (GeOI), stressor such SiGe, SiC to improve mobility at the 90 nm node, epitaxial regrowth of source and drain (raised source and drain), high-k metal gate (HKMG) at the 45 nm node, and 3D structures such as FinFETs and trigates at the 22 nm node.
However, maintaining the device performance and good short channel control is quite challenging beyond the 14 nm technology node. New materials (e.g., III-V semiconductors, Ge, SiGe, graphene, MoS2, WS2, MoSe2, and WS2) and new integration schemes (e.g., nanowires) are needed. Nanowire transistors offer scaling of feature sizes, good short channel control, and enhancement in the device mobility, hence enhancement in device speed.
This disclosure describes nanowires fabrication and integration, and in particular a method and device for parasitic capacitance reduction for nanowire transistors.